Guitar Help

[bronson]

I need some help recording my guitar in GarageBand. I run my guitar through an amp first, then into the line in on my macbook. I then choose my line in as input device in system preferences. The little moniter below it does nothing. Also when I open up GarageBand nothing happens there. Can someone tell me what im doing wrong, or what i am missing.
Thanks

 

[Scarlet Fever]

have you had a look at this preference pane in GarageBand?

 

[bronson]

Yeah, I've done that. I'm thinking that there is a problem with my line in port